Embedded Temperature Sensing in Li-Ion Battery Pouch Cells - Dependence of Cell Orientation and Sensor Location on Measurement Variability

Battery temperature is an important physical property to monitor to ensure good operation and safety, it has a significant impact on cell performance and life. Previously, temperature sensors have been embedded within the centre of cells without considering how sensor location and cell orientation within the thermal chamber impacts the accuracy of the measurement. This work investigates: (i) the in-plane temperature change inside the cell, (ii) the difference in temperature change between internal and corresponding external sensor (cross-plane temperature change) and how they vary in different cell orientations. It was found that the internal temperatures monitored differs more when the cell orientations is altered, as compared to its corresponding external temperatures measured in each orientation. Our data demonstrates that at this scale, experimental methodology has a greater impact on the recorded temperature than the physical location of the sensor (i.e. whether it is on the outside or inside of the cell).